/Engine/Plugins/Runtime/GeometryProcessing/Source/DynamicMesh/Public/Polygroups/PolygroupSet.h
FPolygroupLayerrepresents a polygroup set on aFDynamicMesh3, which supports a "default" group set stored on the mesh, and then N extended group layers stored in the mesh AttributeSet. This struct can represent either.
struct FPolygroupLayer
bool
bIsDefaultLayer
If true, layer is the defaultFDynamicMesh3triangle groups layer
int32
LayerIndex
If bIsDefaultLayer is false, this is the index of the AttributeSet Polygroup Layer